You’ll need to do a little work to continue to receive a common tax exemption.

As part of an effort to prevent duplication and fraud, homeowners who receive the basic STAR (school tax assessment relief) exemption must reapply before Dec. 31.

The state is requiring it because it discovered a number of cases where people were receiving the tax break on multiple homes, said Geoff Gloak, spokesman for the state Department of Taxation and Finance.

“The assessor doesn’t have the ability to know if someone is receiving it in another municipality,” Gloak said.

Senior citizens who receive the enhanced STAR exemption will not have to reapply.

Under state law, property owners are allowed to claim the exemption on their primary residence only. Vacation homes and rental properties do not qualify.

The application period started Monday. All homeowners who claim the exemption will receive letters from the state telling them about the change and how to ensure they continue to receive the tax break. The letters will give instructions, as well as a STAR PIN #, to go online and register. If you do not register by Dec. 31, 2013 the state Department of Taxation & Finance will direct the assessor to remove the BASIC STAR exemption from your parcel for the 2014 assessment roll.

The STAR program, which began in 1998, is one of the most common property tax exemptions but comes with some basic conditions:

— The exemption is available for owner-occupied, primary residences where the resident owners’ and their spouses’ incomes are less than $500,000.

— To reapply, homeowners must provide their Social Security number as well as proof of income.

— Homeowners who bought their home after March 1, 2013, will have to apply again next year.

The average homeowner STAR benefit is $700 annually across the state, and the total savings nearly are $1.9 billion. The average savings of a BASIC STAR exemption on a school property tax bill in Ontario County is $650.

If you or someone you know does not have a computer, you may come to the Real Property Tax Services Office at 20 Ontario St., Canandaigua, or visit your local library, where public access computers are available. You may also call the NYS Department of Taxation and Finance at (518) 457-2036 with questions or to register by phone.